Field of the Invention
This invention relates to a liquid-crystal display apparatus including a liquid-crystal display panel of the active matrix type.
Description of the Prior Art
Some liquid-crystal display apparatuses have a matrix array of 1-pixel-corresponding cells. These cells include different 1-pixel-corresponding areas of a liquid-crystal layer, respectively. Each of the cells further include a storage segment, and a switching transistor connected to the storage segment. The storage segment of each cell can be accessed via the related switching transistor. Scanning circuits control the switching transistors in the cells, and thereby sequentially write 1-pixel-corresponding segments of a video signal into the storage segments of the cells, respectively. In each cell, the storage segment continuously subjects the 1-pixel-corresponding area of the liquid-crystal layer to a signal voltage (an electric field) depending on the 1-pixel-corresponding segment of the video signal. Accordingly, light in the 1-pixel-corresponding area of the liquid-crystal layer is modulated with the 1-pixel-corresponding segment of the video signal.
Japanese published examined patent application 4-67192 discloses such a liquid-crystal display apparatus. In the display apparatus of Japanese application 4-67192, the polarity of an applied video signal is inverted in every field. Thus, the polarity of the video signal during each odd-numbered field is opposite to that during each even-numbered field. Accordingly, in the case where a field frequency is 60 Hz, a liquid-crystal layer is driven at a frequency of 30 Hz. In this case, the brightness of an indicated picture changes every field so that the indicated picture tends to flicker.